Energy efficiency has become a design constraint for various processor devices from battery-powered, mobile devices that execute digital signal processing applications, audio/video codecs, etc., to exascale systems that run large-data scientific computing applications. Existing techniques for improving energy efficiency, such as multiscore scaling, may be limited. Other techniques that may be crucial for performance, for example, may also represent a significant portion of a processor's energy expenditure or may otherwise increase energy expenditure. Existing processor designers, therefore, have struggled to optimize both performance and energy efficiency, among other things.